1. Field of the Invention
The present invention relates to an electronic apparatus with a sensor which can measure atmospheric pressure or water pressure, for example.
2. Background Art
Conventionally, there has been known a wristwatch with a sensor which is provided with a sensor unit such as a pressure sensor. This type of wristwatch with a sensor is constituted such that an opening portion is formed in an apparatus case (exterior case), and a sensor unit is housed in the opening portion from the outside of the apparatus case. In such a wristwatch, the sensor unit is configured to be pushed into the inside of an opening portion by a pushing panel by way of a packing so that the wristwatch can ensure the sealing property of the inside of the apparatus case (see JP-A-4-282489 (patent document 1), for example).
Also there has been known an electronic apparatus with a sensor in which a sensor receiving surface is formed on a panel frame which constitutes a part of a timepiece movement, and a sensor (pressure sensor) is arranged on the sensor receiving surface. Due to such a constitution, the sensor can be fixed to the inside of an exterior case (see JP-A-7-270551 (patent document 2), for example).
In patent document 1 and patent document 2, a detection part of the sensor is arranged to face an outer surface of the case so that the sensor can detect pressure outside the exterior case.
On the other hand, there has been known a timepiece in which a can which can accommodate a sensor therein is formed in the inside of the timepiece case (exterior case) (see JP-UM-A-62-184447 (patent document 3), for example).
A pressure introducing hole through which pressure is introduced is formed in a portion of the can where the sensor is accommodated, and the can is formed by applying drawing to a metal sheet using a press or the like in general. By forming the pressure introducing hole in the can, it is possible to arrange the sensor on a back surface side of the timepiece case.
However, in patent document 1 or patent document 2, to allow the sensor to perform a function thereof satisfactorily, it is necessary to arrange a detection part on an outer surface of the exterior case. That is, it is necessary to ensure a space for arranging the case on an outer surface of the exterior case thus giving rise to a drawback that the exterior case becomes large-sized by an amount corresponding to the space.
On the other hand, to prevent the large-sizing of the exterior case, it is necessary to miniaturize a timepiece display part. This miniaturization of the timepiece, however, gives rise to a drawback that the acquisition of favorable visibility of the timepiece display part becomes difficult.
To the contrary, in patent document 3, the sensor is arranged on a back surface side of the exterior case, and it is sufficient to only form the pressure introducing hole in an outer surface of the exterior case and hence, it may be possible to miniaturize the case compared to the case disclosed in patent document 1 and the case disclosed in patent document 2. In these cases, however, it is necessary to form the can by drawing or the like and hence, it is difficult to offset or incline a center axis of the pressure introducing hole with respect to a center axis of the portion where the sensor is accommodated.
As a result, it is necessary to arrange the timepiece display part or the timepiece movement and the sensor parallel to each other in the surface direction of the display part thus giving rise to a drawback that it is difficult to effectively realize the miniaturization of the timepiece case so that the restriction is imposed on the layout of the sensor.
Further, the increase of a wall thickness of the can is difficult in view of the forming of the can by drawing so that it is difficult to increase the rigidity of the can. As a result, it is difficult to ensure the sealing property between the case and the can. On the other hand, when the can is made large-sized for increasing the rigidity, there arises a drawback that the timepiece case becomes large-sized eventually.